Not applicable.
Not applicable.
1. Field of the Invention
The present invention relates generally to insertion and removal of electronic devices from rack mounted systems. More particularly, the preferred embodiments of the present invention relate to an insertion latch and ejectable pull handle for rack mounted electronic devices. More particularly still, the preferred embodiments of the present invention relate to a handle for electronic devices mounted in a rack system that uses mechanical advantage to supply necessary insertion and removal force, and an insertion latch that holds the ejectable pull handle in a latched position.
2. Background of the Invention
In locations where many computers or electronic devices need to be mounted in a relatively small location, rack mounted systems have been the standard. In a rack mounted system, a plurality of devices may be mounted in the rack generally, and further a plurality of devices may be mounted at each elevation within the rack. These racks typically have a backplane board across a back surface that has one or more electrical connectors. Likewise, the computers or electronic devices that are attached in these rack mounted systems typically electrically couple to each other and to external systems through the electrical connectors mounted on the backplane boards.
Insertion and removal of the electronic devices in early rack mounted systems required significant force, both for removal of the device as well as insertion. With regard to insertion of the electronic devices, the prior art technique was to slide the computer or electronic device into the rack until corresponding pins or a card edge of the electronic device met with the corresponding connector. Once that initial contact was made, or slightly before, the technician or operator then applied an impulse force, e.g., slamming or hitting the electronic device, to supply the necessary force to slide the pins or card edge into the mating connector on the backplane board. Once installed in this manner, the electronic device was typically held in place by screws, knurled knobs or some other locking mechanism to ensure that the electrical connections were not de-coupled, e.g., because of mechanical vibration. Likewise for removal, the operator or technician unlocked or de-latched the mechanism present to hold the electronic device in place, and then supplied significant impulse removal force, e.g., yanked on the electronic device, to overcome the forces tending to hold the card edge or pins within the mating connector.
Significant strides were made in the prior art with the introduction of handles that use mechanical advantage to both insert and remove electronic devices from their backplane board connections. Referring now to FIG. 1, there is shown an electronic device 2 with its card edge connector 4 proximate to a backplane board connector 6. Rather than slamming the electronic device 2 such that the card edge connector 4 mates with the connector 6, as was the early technique, more modern prior art techniques use the mechanical advantage of the handle 8 for insertion and removal. In particular, the handle 8 has a rack hook 10 which couples to the rack into which the electronic device 2 is to be installed. The handle 8 rotates about a pivot point 12 as indicated by the arrows in FIG. 1. Thus, an operator pushing on the handle portion 14 has mechanical advantage because of the greater distance from the handle 14 to the pivot point as compared to the rack hook 10 to the pivot point. Referring now to FIG. 2, there is shown the electronic device 2 with its card edge connector 4 (shown in dashed lines) within the connector 6. However, having now used the mechanical advantage of the handle 8 to insert the electronic device 2, something must be done with the handle 8 to hold it in place. That is, when the electronic device 2 is in the inserted position, there may be some play in the handle which allows it to fall slightly out of place. Not only does this clutter the front of the electronic device, but also may contribute to the electronic device becoming unseated.
Prior art techniques for holding the handle 8 in place involved latching the handle in a latched position by use of the latching area 16 of the handle 8. Because the structure that mates with the latching area 16 must be capable of horizontal displacement to allow the latch 8 to be rotated for removal of the electronic device, prior art devices involved a complicated conglomeration of coil springs and movable parts. While the prior art devices may do the job of holding the handle 8 in the latched position, their complexity to build and repair make them undesirable.
Thus, what is needed in the art is an insertion latch mechanism that does not use the coil springs and complicated moving parts common in the prior art. Such a system should be relatively simple, have few moving parts, and should be easy to install and remove.
The problems noted above are solved in large part by an insertion latch and ejectable pull handle system. The insertion latch of the preferred embodiment has a mounting portion that securely attaches to the electronic device. By securely attaching, substantially no rotation is allowed of the mounting portion of the insertion latch. The insertion latch also comprises a latching head adapted to mate with a latching area of the ejectable pull handle. This latching head thus holds the ejectable pull handle in a latched position when the electronic device is installed in the rack. Between the latching head and the mounting portion is a flexible arm comprising a compression member and a tension member. In a latched or rest position, the compression member is not compressed, and the tension member is not under tension; however, when the latching head is displaced, the compression member is placed in compression and the tension member is placed in tension. These two members, acting in combination, provide the necessary restoring force for the latching head once the displacing force has been removed. Displacing of the latching head takes place either by an operator or technician pushing the latching head to release the ejectable pull handle, or by actuation of a displacement arm on the ejectable pull handle during the latching operation.
The preferred embodiments of the present invention also comprise a force application surface on the ejectable pull handle, and a leaf spring securely attached to the mounting portion of the insertion latch and contacting the force application surface. The leaf spring provides the necessary force to push the ejectable pull handle to an intermediate position, such that an operator or technician can grab the handle and rotate it for removal of the electronic device. The force application surface on the ejectable pull handle is designed such that force provided by the leaf spring is directed substantially tangential to the point of rotation, regardless of the handle position.